1. Field of the Invention
The present invention relates to an offline programming device and, in particular, to an offline programming device for easily correcting the difference between an offline simulation and a field operation, in relation to the position of a robot relative to an object.
2. Description of the Related Art
When an object to be worked or a workpiece should be worked using a robot, in the prior art, the positional relation between the robot and the workpiece is calculated offline by using CAD or CAM Systems. However, as this method can determine only a rough layout of the robot, the method is not suitable when high positional accuracy is required, for example, in the case of spot welding.
To that end, for example, Japanese Patent Publication No. 2,767,417 discloses a control device for measuring the accurate position of a workpiece by means of a camera mounted on a robot. In detail, the control device may image three reference points on the workpiece by using the camera so as to calculate the three-dimensional positional relation between the robot and the workpiece. Due to the calculated result, the positional relation previously obtained offline may be corrected so as to improve the positional accuracy.
The accuracy of the positional relation between the robot and the workpiece may be improved by correction using a camera or a vision sensor. However, a measuring program for imaging the reference point of the workpiece using the vision sensor is created, by an operator, by trial and error, as in the case of conventional programming. Therefore, it takes time to create an offline program including the measuring program. Further, if an operation check of the offline program is not adequately or sufficiently carried out, the robot may interfere with the workpiece in this field. It also takes time to avoid this interference.